Dual inlet rotary tool

ABSTRACT

A rotary device having a housing that has a first fluid inlet and second fluid inlet. A rotor is rotatably mounted in the housing and is in communication with the first and second fluid inlets.

FIELD OF THE INVENTION

This invention relates generally to rotary tools. In particular, this invention relates to machine mounted pressurized fluid driven rotary tools.

SUMMARY OF THE INVENTION

In one embodiment, the present invention relates to a rotary device having a housing that has a first fluid inlet and a second fluid inlet. A rotor is rotatably mounted in the housing and is in communication with the first and second fluid inlets.

The present invention also relates to a method for connecting a rotary tool to a fluid source by providing a housing and a rotor mounting in the housing. First and second fluid inlets are provided in the housing, which are each in communication with the rotor. A plug is inserted into the first fluid inlet and the second fluid inlet is connected to a high pressure fluid source.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a rotary tool according to the present invention.

FIGS. 2A and 2B are side views of the rotary tool according to the present invention as mounted to a CNC machine.

FIGS. 3A and 3B are side views of the rotary tool according to the present invention as mounted to a machine fixture.

DETAILED DESCRIPTION

Referring to FIG. 1, an exemplary rotary device according to the present invention is shown generally at 10. The exemplary device described herein is a pneumatic tool having a turbine rotor powered by oil-free high pressure air, however, it will be understood that the concepts of the current invention could be used or adapted for use for any rotary tool having any type of fluid driven motor, such as a vane motor, and powered by any type of compressed fluid.

As shown in FIG. 1, the rotary tool 10 generally has a housing 13 formed by a front section 12, a back section 14 threaded to the front section 12, and an end cap 24 threaded to the back section 14. The front section 12 includes a portion having a relatively large diameter to which a fixture can be attached, as described in more detail below. The portion of the front section 12 having the relatively large diameter includes a motor chamber 15 formed on an inside portion thereof and a rotor 16 mounted within the motor chamber 15.

The back section 14 of the housing 13 includes a first fluid inlet 34 that has a longitudinal axis B that is generally perpendicular to an axis of rotation A of the rotor 16. The first fluid inlet 34 is in communication with the rotor 16 and is adapted to receive a pressurized fluid and transmit the pressurized fluid to the rotor 16. The first fluid inlet 34 is formed by a bore extending through the sidewall of the back section 14 of the housing 13 and is adapted to receive a hose from a high pressure air source, an inlet adapter, or a plug, as described in more detail below, for example by having threads formed on at least a portion of the bore. An inlet adapter 36 is threaded into the first fluid inlet 34 and has a bore 37 therethrough that is in communication with the first fluid inlet 34. The inlet adapter 36 is adapted to receive a hose from a high pressure air source or a plug, as described in more detail below, for example by having threads 38 formed on at least a portion of the bore.

The back section 14 of the housing 13 also includes a second fluid inlet 32 that has a longitudinal axis that is generally parallel to the axis of rotation A of the rotor 16. The second fluid inlet 32 is in communication with the rotor 16 and is adapted to receive a pressurized fluid and transmit the pressurized fluid to the rotor 16. The second fluid inlet 32 is formed by a bore extending through the end of the back section 14 of the housing 13. A generally cylindrical shank 30 having a longitudinal axis that is generally parallel to the axis of rotation A of the rotor 16 is integrally formed to the back section 14 of the housing 13, extends from the end of the back section 14, and can be used as a mount to connect the rotary tool 10 to a machine, as is described in more detail below. The shank 30 has a bore 33 extending therethrough, which is in communication with the second fluid inlet 32, to allow the shank 30 to receive a pressurized fluid and transmit the pressurized fluid to the second fluid inlet 32, as described in more detail below. The shank 30 is adapted to receive a hose from high pressure air source or a plug, as described in more detail below, for example by having threads 35 formed on at least a portion of the bore. A pair of o-rings 31 sit within indentations in the outer wall of the shank 30.

Inside of the back section 14 is a muffler 26, which may be composed of a felt-like material and is adapted for muffling the noise caused by exhausted fluids. In addition, the end cap 24 includes one or more holes 21 each having a predetermined diameter which are adapted to allow the pressurized fluid to escape from the motor chamber 15.

A rotor 16, having an axis of rotation A, is mounted within the motor chamber 15 such that the rotor 16 can rotate therein. As described herein, the rotor 16 is a reaction turbine-type rotor, such as that described in U.S. Pat. No. 4,776,752 to Davis, which has a common assignee with the present invention, and the disclosure of which is hereby incorporated by reference. However, the present invention is not so limited and may be applied to rotary devices having other types of motors. In operation, pressurized air is directed to the rotor 16 from the first fluid inlet 34 and/or the second fluid inlet 32. As the air enters the rotor 16 it enters a first annular chamber 50, flows around a resilient valve ring 52 through radial holes 54 in annular wall 60 into a second annular chamber 56, where it is directed through nozzles 58, thereby imparting rotation to the rotor 16 and therefore the rotatable shaft 18. The pressurized fluid is expelled from the rotor 16 through the nozzles 58 and passes into the motor chamber 15, through the muffler 26, and exits the rotary tool 10 through the holes 21 in the end cap 24 to atmosphere. As the pressurized fluid is directed into the rotor 16, rotation increases to a pre-selected maximum. Centrifugal forces acting on resilient valve ring 52 tend to cause radial expansion of the ring 52, however, the inner surface of the annular wall 60 supports the valve ring 60, except at radial holes 54. This enables the radial expansion of the valve ring 52 to be directed into the holes 54 so as to cause a controlled elastic deformation of valve ring 52. In operation, as the resilient valve ring 52 deforms, it approaches the ends of radial holes 54. As the distance narrows sufficiently, fluid flow through the radial holes 54 is restricted and rotating forces reduced. As drag forces acting on the system and rotating forces reach equilibrium, the forces acting on the resilient valve ring 52 will also be in equilibrium. This results in a constant rotary speed. If drag forces increase, the equilibrium would be disrupted, and the forces on the resilient valve ring 52 will retract the valve ring 52 from its closest proximity to radial holes 54, allowing additional fluid flow until another equilibrium is established. If for any reason the turbine should exceed the desired governed speed, the resilient valve ring 52 will move to restrict pressure fluid flow even further until sufficient overspeed will cause all flow to stop, thereby incorporating an overspeed safety.

A rotatable shaft 18 is attached at one end to the rotor 16 and at the other end to a collet 22, which is used to hold a tool (not shown), such as a grinding-type tool. The shaft 18 is rotatably supported by bearings 20 which, in turn, are respectively secured to the front section 12 of the housing 13.

As shown in FIG. 2A, to mount the rotary tool 10 to a CNC machine, or other machine having a chuck for mounting the tool, the tool 10 is secured to the machine by inserting the shank 30 into the chuck 40 of the machine (not shown) and securing it thereto. If the machine provides high pressure air through the chuck 40, the bore 33 in the shank 30 (see FIG. 1) is left open and the high pressure air is supplied to the rotor 16 through the second fluid inlet 32 (see FIG. 1). When secured in the chuck 40, the o-rings 31 (see FIG. 1) prevent the high pressure air from escaping around the outside of the shank 30. The first fluid inlet 34 (see FIG. 1) is blocked by threading a plug 42 into the inlet adapter 36. Alternatively, if an inlet adapter 36 is not used, the first fluid inlet 34 can be blocked by threading a plug 42 directly into the first fluid inlet 34. As can best be seen in FIG. 1, when connected in this way, air from the high pressure air source enters the tool 10 through the shank 30, passes through the bore 33 in the shank 30 to the second fluid inlet 32, and from the second fluid inlet 32 to the rotor 16, where the high pressure air drives the rotor 16. The high pressure air that is expelled from the rotor 16 enters the motor chamber 15, passes through the muffler 26, and is expelled from the tool 10 through the holes 21 in the end cap 24.

Alternatively, as shown in FIG. 2B, the second fluid inlet 32 (see FIG. 1) could be blocked by threading a plug 42 into the shank 30 and the hose 46 of a high pressure air source (not shown) could be connected to the inlet adapter 36 to provide high pressure air to the rotor 16 through the first fluid inlet 34 (see FIG. 1). Alternatively, if an inlet adapter 36 is not used, the hose 46 could be connected directly into the first fluid inlet 34. As can best be seen in FIG. 1, when connected in this way, air from the high pressure air source enters the tool 10 through the inlet adapter 36, passes through the bore 37 in the inlet adapter 36 to the first fluid inlet 34, and from the first fluid inlet 34 to the rotor 16, where the high pressure air drives the rotor 16. The high pressure air that is expelled from the rotor 16 enters the housing 13, passes through the muffler 26, and is expelled from the tool 10 through the holes 21 in the end cap 24.

As shown in FIG. 3A, to mount the rotary tool 10 to a machine having a fixture 44, such as a robotic arm, the tool 10 is secured to the fixture 44 by clamping the housing 13 within the fixture 44. Alternatively, depending on the machine and the desired usage, the tool 10 can also be secured to the fixture 44 by clamping the shank 30, rather than the housing 13, within the fixture 44, as shown in phantom. The shank 30 is connected to the hose 46 of a high pressure air source (not shown) to provide high pressure air to the rotor 16 through the second fluid inlet 32 (see FIG. 1). The first fluid inlet 34 (see FIG. 1) is blocked by threading a plug 42 into the inlet adapter 36. Alternatively, if an inlet adapter 36 is not used, the first fluid inlet 34 can be blocked by threading a plug 42 directly into the first fluid inlet 34. As can best be seen in FIG. 1, when connected in this way, air from the hose 46 enters the tool 10 through the shank 30, passes through the bore 33 in the shank 30 to the second fluid inlet 32, and from the second fluid inlet 32 to the rotor 16, where the high pressure air drives the rotor 16. The high pressure air that is expelled from the rotor 16 enters the housing 13, passes through the muffler 26, and is expelled from the tool 10 through the holes 21 in the end cap 24.

Alternatively, as shown in FIG. 3B, the inlet adapter 36 could be attached to the hose 46 of the high pressure air source (not shown) to provide high pressure air to the rotor 16 (see FIG. 1) through the first fluid inlet 34 (see FIG. 1). Alternatively, if an inlet adapter 36 is not used, the hose 46 could be attached directly to the first fluid inlet 34. The second fluid inlet 32 (see FIG. 1) is then blocked by threading a plug 42 into the end of the shank 30. As can best be seen in FIG. 1, when connected in this way, air from the high pressure air source enters the tool 10 through the inlet adapter 36, passes through the bore 37 in the inlet adapter 36 to the first fluid inlet 34, and from the first fluid inlet 34 to the rotor 16, where the high pressure air drives the rotor 16. The high pressure air that is expelled from the rotor 16 enters the housing 13, passes through the muffler 26, and is expelled from the tool 10 through the holes 21 in the end cap 24.

As can be seen from the above description, the current invention allows a single rotary tool to be used with almost any machine, any mounting configuration, and any fluid inlet configuration desired, rather than having different tools for each.

The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The descriptions were selected to best explain the principles of the invention and their practical application to enable other skills in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention not be limited by the specification, but be defined by the claims set forth below. 

1. A rotary device, comprising: a housing having a first fluid inlet and a second fluid inlet; a rotor rotatably mounted in the housing and in communication with the first and second fluid inlets.
 2. A rotary device, as recited in claim 1, wherein the first fluid inlet has a longitudinal axis transverse to an axis of rotation of the rotor and is adapted to receive a pressurized fluid and transmit the pressurized fluid to the rotor.
 3. A rotary device, as recited in claim 2, wherein the first fluid inlet comprises a bore extending through a side of the housing.
 4. A rotary device, as recited in claim 1, wherein the second fluid inlet has a longitudinal axis parallel to an axis of rotation of the rotor and is adapted to receive a pressurized fluid and transmit the pressurized fluid to the rotor.
 5. A rotary device, as recited in claim 4, wherein the second fluid inlet comprises a bore extending through an end of the housing.
 6. A rotary device, as recited in claim 1, further comprising a mount connected to an end of the housing for connecting the rotary device to a machine.
 7. A rotary device, as recited in claim 6, wherein the mount is adapted to receive a pressurized fluid and transmit the pressurized fluid to the second fluid inlet.
 8. A rotary device, as recited in claim 6, wherein the mount comprises a bore therethrough, the bore being in communication with the second fluid inlet.
 9. A rotary device, as recited in claim 6, wherein the mount is integral with the housing.
 10. A rotary device, as recited in claim 6, wherein the mount comprises a shank connected to and extending from the end of the housing.
 11. A rotary device, as recited in claim 10, wherein the shank is adapted to receive a pressurized fluid and transmit the pressurized fluid to the second fluid inlet.
 12. A rotary device, as recited in claim 10, wherein the shank comprises a bore therethrough, the bore being in communication with the second fluid inlet.
 13. A rotary device, as recited in claim 10, wherein the shank is integral with the housing.
 14. A rotary device, as recited in claim 1, further comprising an inlet adapter, removably connected to the housing and in communication with the first fluid inlet, for connecting the housing to a high pressure fluid source.
 15. A rotary device, as recited in claim 14, further comprising a plug adapted to prevent the flow of fluid through the inlet adapter.
 16. A rotary device, as recited in claim 1, further comprising a plug adapted to prevent the flow of fluid through the first or second fluid inlet.
 17. A method for connecting a rotary tool to a fluid source, comprising the steps of: providing a housing and a rotor mounted in the housing; providing a first fluid inlet in the housing in communication with the rotor; providing a second fluid inlet in the housing in communication with the rotor; inserting a plug into the first fluid inlet; and connecting the second fluid inlet to a high pressure fluid source.
 18. A method for connecting a rotary tool to a fluid source, as recited in claim 17, further comprising the step of providing a mount connected to an end of the housing for connecting the housing to a machine.
 19. A method for connecting a rotary tool to a fluid source, as recited in claim 17, further comprising the step of providing a shank connected to and extending from an end of the housing for connecting the housing to a machine.
 20. A method for connecting a rotary tool to a fluid source, as recited in claim 19, further comprising the step of providing a bore through the shank adapted to receive a pressurized fluid and transmit the pressurized fluid to the first or second fluid inlet.
 21. A method for connecting a rotary tool to a fluid source, as recited in claim 17, further comprising the step of providing an inlet adapter for connection to the first or second fluid inlet for connecting the fluid inlet to a high pressure fluid source. 